1. Field of the Invention
This invention relates to the field of wastewater treatment and more specifically to the field of post-decontamination wastewater treatment.
2. Background of the Invention
Vessels in refineries and chemical facilities are decontaminated for various purposes. For instance, vessels may be decontaminated to allow personnel to safely enter the vessels. Different methods have been used to decontaminate vessels. A conventional method includes using washes of aqueous solutions that contain reactive chemicals. The conventional washes typically contain additives having properties of a surfactant to facilitate penetration of oily films and a reactive capability to destroy dangerous sulfides such as hydrogen sulfide and pyrophoric iron sulfides.
Problems involved with such conventional methods include handling the used solution after the decontamination operation has been completed. For instance, after completion of the decontamination operation, the solution may be considered a waste and is typically handled by wastewater facilities at the refinery or chemical facility. In some refineries or chemical facilities, the wastewater facilities are not sufficient to handle such wastewater. Such problems may include limited real estate at the refinery, facility or offshore platform, which may prevent the wastewater facility from being able to handle volumes of wastewater that have organic chemicals. Additional drawbacks include such wastewater having a chemical oxygen demand (COD) greater than that typically desired by conventional facilities.
Consequently, there is a need for an improved method for treating wastewater. Additional needs include an improved method for reducing the chemical oxygen demand of wastewater.